JPH0218118A - Speed change gear for tractor - Google Patents

Abstract

PURPOSE:To perform smooth turning of a tractor safely with front wheels accelerated or changed in speed only when the speed is low for a four-wheel drive speed change gear, by arranging an acceleration gear which accelerates and changes speed of front wheels, at the low speed position of a sub speed change gear. CONSTITUTION:A speed change gear 3, is provided with a plurality of main speed change gear 10, 11 which form a main speed change gear, and a plurality of sub speed change gear 12, 13 which form a sub speed change gear 4 are arranged between an input shaft 8 and an output shaft 9. To a multiple speed shaft 20 that is arranged in parallel with the lower side of the output shaft 9, each of gears 24, 25 which are constantly engaged with a low speed and a high speed gears 22, 21, respectively, that are furnished to a front wheel transmission shaft 19, and a disc clutch 26 which frictionally gears between each of the gears 24, 25, are arranged, to form an acceleration gear 5. A gear ratio for the front wheel gear shaft 19 via the disk clutch 26 is almost double the gear ratio of the front wheel transmission shaft 19 via a clutch 23, through the connection of the disk clutch 26 with a piston 27, and the high speed transmission at the almost doubled acceleration ratio is thus possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a transmission for a tractor, and is intended to facilitate turning by transmitting the front wheels to a high-speed shifting position during turning steering during tractor work. It is something to do.

Background Art and Problems to be Solved by the Invention Tractors travel at relatively low speeds while working and at high speeds while traveling on the road. For this reason, when turning and steering, if the front wheels are geared up to twice the normal speed to facilitate turning, this increased speed change will be performed when driving on the road. If this happens, the vehicle will make a sharp turn while traveling at high speed, which is dangerous as it will easily fall over and the operator will be easily thrown off the seat.

Means for Solving the Problems The present invention provides a four-wheel drive transmission M (3) that drives front wheels (1) and rear wheels (2).
4) A tractor transmission device is provided with a speed increasing transmission device (5) that increases the speed of the front wheel (1) at the low speed position.

Functions and Effects of the Invention When the tractor is running, the gears are normally changed by the main transmission of the transmission (3), and the rear wheels (2) and front wheels (1) are rotated. The sub-transmission device (4) has a high-speed range (H) and a low-speed range (L), and when driving at relatively high speeds such as when driving on the road, the sub-transmission device (4) shifts to the high-speed position (H) and performs work. When doing so, sub-shift to the low speed range (L).

When turning and steering during work driving, for example, by turning the steering wheel over a certain angle, the speed-increasing transmission device (5)
is transmitted at variable speeds, and the front wheels (1) are rotated at high speed at variable speeds, thereby making turning smooth.

High-speed transmission using such a speed-increasing transmission device @(5) is as follows.

It is not performed when the sub-transmission device (4) is in the high speed range (H), and is performed only when it is in the low speed range (L). Moreover, since the speed increase of the front wheels (1) is performed by installing the speed increase transmission device (5) in the four-wheel drive speed change transmission device (3), the configuration is N-clean and the speed increase can be performed accurately. maintain control,
Safety can be increased.

In the embodiment, when the tractor body is rotated, the transmission case (6
) is connected to the main speed change transmission device (3) between an input shaft (8) that receives input from the engine (7) and an output shaft (9) that transmits power to the rear axle of the rear wheels (2). In addition to the main transmission gear (Iω (10) that constitutes the device, the auxiliary transmission [+4]
A sub-transmission gear (17J (11) is provided, which constitutes the sub-transmission gear (17J), and when the sub-transmission gear 0?
is transmitted at low speed and switched between road speed and work speed. 04 is the cockpit (19 front steering wheel (IB)
The main transmission gear (1ω (111) provided above and below is the main transmission lever for shifting the gear, (i force is the auxiliary transmission lever for shifting the auxiliary transmission gear 0♂ (+3). (11 is the transmission gear (1)
This is the main transmission shaft where υ(11) etc. are provided.

A front wheel transmission shaft (1'fl) and a double speed shaft are provided parallel to the lower side of the output shaft (9). A low speed gear (23) is rotatably provided so that the high speed gear 2+1 rotates integrally with the rotated high speed gear 2+1, and furthermore, this low speed gear Q3 has a
A clutch (2) that rotates integrally with this front wheel transmission shaft +In is provided so that it can be turned on and off, and the front wheel transmission shaft (
1! The low-speed transmission rotation of II is performed by engaging this clutch (2).

The double speed axis c! G is provided with a gear (c) that is always in mesh with the low speed gear (23), 12 gears that are always in mesh with the high speed gear f2++, and a disc clutch r2e that transmits friction between these two gears. 12e is turned on and off by a hydraulic piston (5), from this low speed gear Q3 to gear Q4 and this clutch Q.
e, gear 4 and high speed gear? 1) etc., the front wheel transmission shaft (19) is connected directly to the front wheel transmission shaft (19) by the clutch, and then the low speed gear (2δ) is directly connected to the front wheel transmission shaft (128 and (2 ), the shifter (2I) is connected, and when the disc clutch (2e) is engaged, the clutch (2) is disengaged, and the disc clutch (2) is connected.
When the clutch is turned off, the clutch is engaged and engaged.

I2 is the old front export power shaft, and the front end of the front wheel transmission shaft (!9) can be engaged with the clutch OI, and this clutch 01 enables four-wheel drive or rear-wheel drive. Further, this output shaft C9 is connected to the front wheels (1) by a transmission shaft Oυ.

(2) is an outer shaft that can freely rotate around the outer periphery of the main transmission shaft OB, and has a sub-transmission gear (11 gears (to) to be meshed with it). (B) is an outer shaft that can freely rotate around the outer periphery of the output shaft (9), and It has a gear (to) that is meshed with the transmission gear αδ.

By operating the sub-transmission gear (1?J (13), the low speed range (
In L), by manually engaging the clutch (to), the front wheel transmission shaft (to) is transmitted and rotated at a low speed. This low speed range (
When the clutch (2e) is engaged in conjunction with the steering operation etc. at the time of L), the speed increasing transmission device (5) becomes the transmission state,
The front wheel transmission shaft (1 gear) transmits speed-up rotation. Also, when the auxiliary transmission gear (1 gear) is engaged with the gear (to), the high speed gear G!+1
The front wheel transmission shaft (Igl) is also meshed and rotated to transmit high speed transmission.

However, at this time, the auxiliary transmission gear (1 old, low speed gear Q3
Since the disc is disengaged from the clutch, deceleration or speed increase will not occur even if the clutch (to) is engaged or the disc clutch I2e is engaged.

The OQ is a tilling device connected to the rear side of the tractor, which can be raised and lowered under the control of a lift arm, and is configured to transmit tilling power through a power take-off shaft.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a longitudinal sectional view of a portion thereof, and FIG. 2 being a side view. In the figure, reference numeral (1) indicates a front wheel, (2) a rear wheel, (3) a speed change transmission, (4) an auxiliary transmission, and (5) a speed increase transmission.

Claims (1)

[Claims] In a four-wheel drive variable speed transmission (3) that drives front wheels (1) and rear wheels (2), a speed increasing transmission that increases the speed of the front wheels (1) at a low speed position of an auxiliary transmission (4). Device (5)
A tractor transmission device equipped with a